1. Field of the Invention
The present invention relates to a method of and an apparatus for manufacturing a cylindrical slide bearing.
2. Prior Art
There have been employed various methods of manufacturing a cylindrical slide bearing such as those comprising the steps of employing a bearing material formed by layering a bearing metal alloy on a steel plate forming an inner peripheral surface of the bearing and then subjecting the bearing material to a bending processor, thereby forming a cylindrical shape. As the bearing material, there has been employed a semiprocessed product having a U-shape as a primary round product, and the method comprises the steps of inserting a core into the semiprocessed product, subjecting the semiprocessed product to a one time pressing process, i.e. giving the semiprocessed product one pressing by a press unit which is provided with a die and a punch having respectively recessed portions of semi-cylindrical shapes.
However, the bearing made by the above methods is inferior in the round accuracy thereof when subjected to one pressing and is liable to have a heptagonal shape at worst. Hence, the core and the semiprocessed product are respectively manually rotated for subjecting the semiprocessed product to a plurality of pressings, which involves unstable productivity with low accuracy. It is desirable that the cylindrical slide bearing is in general pressed into and securely fixed to a housing and brought into contact with the housing having superior heat radiation property. Therefore, it is desirable that the cylindrical slide bearing be formed in a complete circular shape.